Basically, the power is entirely in the user’s hands. However, it seems that Apple is anticipating that some developers might try to skirt around the prompt by offering users “rewards” if they were to enable tracking. In an update to its Human Interface Guidelines, Apple says that they will ban apps that attempt to try to trick the user into enabling tracking or by offering up a reward or incentive to do so.
To Apple’s credit, it seems that they have learnt from past instances where some developers and apps reward users for skirting the App Store’s rules. Of course, there is the question of whether or not Apple will be able to catch apps that violate their guidelines. In recent months, there has been an increasing number of reports of how scam apps that clearly violate Apple’s terms of agreement are still allowed to remain on the App Store.
Some of these apps have reportedly been making millions, and in one case, a gambling app was actually hidden behind a game designed for kids.